You can use Cloud Datastore to store application data from your App Engine app. Cloud Datastore is a database built for automatic scaling, high performance, and ease of app development.
You can integrate Cloud Datastore into your PHP 7 app using the Google Cloud Client Library. The library provides an idiomatic PHP 7 client to Cloud Datastore, providing APIs to store and retrieve data using Cloud Datastore in an App Engine app.
Elaborate Datastore queries require one or more indexes,
which must be specified in an
that you upload along with your app. This file may be created manually, or
generated automatically while testing your app locally.
For more information on Cloud Datastore, including optimizations and concepts, see the Cloud Datastore documentation.